The deployment of the stealth bombers was clearly meant to deliver a potent message to Pyongyang about the US commitment to defending South Korea against any aggression as military tensions on the Korean peninsula soar.

It came after theÂ North severed its last-remaining military hotline with South Korea on Wednesday and put its rocket units on combat status with a threat to target US bases in the Pacific region.

The two B-2s, from Whiteman Air Force base in Missouri, flew the 13,000 mile (20,800 kilometre) round-trip in a “single continuous mission”, dropping dummy ordnance on a target range in the South, the US military said in a statement.